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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada Singleton Pattern
Date: Mon, 13 Sep 2004 17:33:24 +0200
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Date: 2004-09-13T17:33:24+02:00
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On Mon, 13 Sep 2004 15:04:27 GMT, Luca Stasio wrote:

> Hi, there is a way to implement the Singleton Pattern in Ada?
> There are some examples out there?
> Thanx.

package Foo is
   type Singleton (<>) is limited private;
   ... -- Public interface subroutines

   The_Only_One : constant Singleton; -- The value
private
   type Singleton is new Integer; -- Any implementation you want
   The_Only_One : constant Singleton := 5;

The public view of Singleton is unconstrained and limited, which prevents
it from either being copied or declaring new objects of this type.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de